The present invention relates to compositions comprising 8-hydroxyquinaldine and N-acyl taurates. particularly to compositions further comprising a polymer, and more particularly to compositions where the polymer is a rubber.
The present invention, in its most general form, is a composition comprising 8-hydroxyquinaldine and an N-acyl taurate. 8-hydroxyquinaldine is also known as 8-hydroxy-2-methylquinoline. The general formula of the N-acyl taurate may be expressed as 
Here, the acyl group may be generally any hydrocarbon or substituted hydrocarbon group. Generally, in the N-acyl taurate, the acyl group will have in the range of 8 to 20 carbon atoms. In formula (1), this would correspond to R1 having 7 to 19 carbon atoms. In the above formula, group R2 may be hydrogen or an alkyl group containing 1 to 20 carbon atoms. If group R2 is an alkyl group, the N-acyl taurate is, more specifically, an N-acyl-N-alkyl taurate.
Generally, the N-acyl taurate will be provided in the composition in the form of a salt, for example, a metal salt, such as the sodium salt. However, the N-acyl taurate may conceivably be provided in the acid form (N-acyl taurine).
N-acyl taurates and, more specifically, N-acyl-N-alkyl taurates are known, and one skilled in the art can make any of a wide variety of these compounds. The Examples to be described use sodium N-lauroyl-N-methyl taurate, which is commercially available, but the invention is not limited to use of this compound. Other compounds consistent with formula (1), include sodium N-oleyl taurate, sodium N-oleyl-N-methyl taurate, sodium N-cocoyl-N-methyl taurate, sodium-N-myristoyl-N-methyl taurate, sodium-N-palmitoyl-N-methyl taurate, and sodium-N-palmitoyl-N-stearyl taurate, as well as the potassium and lithium salts and other salts of these compounds.
Among the utilities of the compositions of the present invention, of particular interest is the use in elastomer compositions. Compositions comprising 8-hydroxyquinaldine and an N-acyl taurate and further comprising a base polymer may be useful elastomer compositions. Here, a base polymer may be generally any polymer, that is a material of relatively high molecular weight which is made of multiple linked units which were derived from a monomer or different monomers.
Among the base polymers which may be part of compositions of the present invention are base rubbers. Among the rubbers to which the invention is applicable are nitrile rubbers, hydrogenated nitrile rubbers, ethylene-propylene rubbers, copolymers of vinyl acetate and ethylene terpolymers of ethylene, propylene and a non-conjugated diene, natural rubbers, polybutadiene, polyisobutylene, butyl rubber, halogenated butyl rubber, copolymers of butadiene with one or more polymerizable ethylenically unsaturated monomers, such as styrene, acrylonitrile, methyl methacrylate, polyacrylates, polyethers and polymers of substituted butadienes, such as chlorobutadiene and isoprene. Mixtures of different rubbers or rubbers and plastics (e.g., nitrile rubber and polyvinyl chloride ) may, of course, also be used.
In the present invention, Examples are presented in which the base rubber is a hydrogenated initrile rubber, but other base rubbers and base polymers or elastomers may also be used in making compositions of the present invention.
In compositions of the invention comprising a base rubber, the 8-hydroxyquinaldine may be present at 0.05 to 100 parts, or more particularly at 0.1 to 30 parts, per 100 parts of base rubber (by weight). The N-acyl taurate compound may be present at 0.05 to 100 parts, or more particularly at 0.1 to 20 parts, per 100 parts of base rubber.
In addition to base polymer, compositions of the present invention may also comprise any of a variety of components commonly used in polymer compositions, as discussed below.
For example, compositions of the present invention may further comprise a metal oxide. This metal oxide may be an alkaline earth metal oxide. for example, magnesium oxide. When present. the metal oxide will generally be used at 2 to 50 parts, or more particularly at 3 to 10 parts, per 100 parts of the base rubber.
Compositions of the present invention may further comprise a filler or more than one filler. The filler may be, for example, a clay, a silica, a high-pH mineral filler. or may be a carbon black. When present, the filler will generally be used at 20 to 200 parts. or more particularly at 40 to 100 parts, per 100 parts of the base rubber.
Compositions of the present invention may further comprise a plasticizer or more than one plasticizer. Many compounds are known in the art to serve as plasticizers, for example trioctyl trimellitate. When present, the plasticizer will generally be used at 2 to 100 parts, or more particularly at 5 to 20 parts, per 100 parts of the base rubber.
Compositions of the present invention may further comprise an antioxidant, or more than one antioxidant. Many compounds are known in the art to serve as antioxidants. Examples include the amine antioxidants, such as 4,4xe2x80x2-bis(xcex1,xcex1-dimethylbenzyl)diphenylamine, and benzimidazoles, such as Zn salt of 2-mercapto 4 (5)-methylbenzimidazole. When present, the antioxidant will generally be used at 0.5 to 5 parts, or more particularly at 1 to 3 parts, per 100 parts of the base rubber.
Compositions of the present invention may also further comprise a curing (vulcanizing) agent or agents. Generally, these agents are added before a heat-treating step to cure (vulcanize) the composition. The vulcanizing agents will be chemically present in the composition before the heat-treating step, but in some cases will chemically react with the composition during the heat-treating step such that the vulcanizing agent might no longer be present after heat-curing (vulcanizing). The present invention is intended to encompass both the compositions before and after the heat-curing (vulcanizing) step. That is, even if a component in the pre-vulcanized composition (that is, before heat-curing) has fully reacted during heat-curing, the cured (vulcanized) composition can be considered to be a composition made by heat-curing the pre-cured (pre-vulcanized) composition.
Examples of curing agents or curatives (vulcanizing agents) which may be added include sulfur, sulfur donors and organic peroxides, such as xcex1,xcex1-bis(t-butyl peroxide) diusopropylbenzene. When present, the curative or curatives will generally be used at 1 to 15 parts, or more particularly at 1.5 to 10 parts, per 100 parts of the base rubber.
In making compositions of the present invention, a polymer composition is admixed using conventional rubber mixing equipment such as an internal mixer, 2-roll mill, extruder or the like. In one embodiment of a formulation method, all ingredients except the curing agent (or agents) are added to the mixture and mixed for several minutes or until the temperature has reached about 110 to 170xc2x0 C. to make a master batch. This masterbatch is the dumped onto a cool 2-roll mill for final mixing and the curing agents are mixed in on the mill.
As an alternative, second embodiment of the formulation method, all ingredients including the curing agent (or agents) are admixed and the mixture is dumped at 90 to 120xc2x0 C.
As an alternative third embodiment of the formulation method, a two-pass mix can be conducted in which the initial mix masterbatch is added back into the mixer, curative is added, and the mixture is mixed for several minutes or until the mixing temperature reaches 90 to 120xc2x0 C., and then dumped to a cool finishing 2-roll mill.
After mixing, the composition may extruded or molded, and is cured by heat-treatment, typically at a temperature or temperatures in the range of 150 to 200xc2x0 C.
In the process of the present invention, it is convenient to add the 8-hydroxyquinaldine to the mixture in the form of a premixture of 8-hydroxyquinaldine on a base rubber. If no other active ingredients are present, such a premixture can be considered to consist essentially of 8-hydroxyquinaldine and the base rubber. It is also possible to prepare a premixture of 8-hydroxyquinaldine and the N-acyl taurate on a base rubber, which can be considered to consist essentially of the 8-hydroxyquinaldine, the N-acyl taurate and the base rubber.